Renal artery

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Artery: Renal artery
Renal arteries branching left and right from the aorta (in red), viewed from behind with the spine removed
1. Renal pyramid
2. Efferent artery
3. Renal artery
4. Renal vein
5. Renal hilum
6. Renal pelvis
7. Ureter
8. Minor calyx
9. Renal capsule
10. Inferior renal capsule
11. Superior renal capsule
12. Afferent vein
13. Nephron
14. Minor calyx
15. Major calyx
16. Renal papilla
17. Renal column
Latin Arteria renalis
Gray's p.610
Supplies Kidneys
Source Abdominal aorta   
Branches Inferior suprarenal artery, segmental arteries
Vein Renal vein
MeSH Renal+Artery

The renal arteries normally arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle with the aorta.

The renal arteries carry a large portion of total blood flow to the kidneys. Up to a third of total cardiac output can pass through the renal arteries to be filtered by the kidneys.

The arterial supply of the kidneys is variable and there may be one or more renal arteries supplying each kidney. It is located above the renal vein. Supernumerary renal arteries (two or more arteries to a single kidney) are the most common renovascular anomaly, occurrence ranging from 25% to 40% of kidneys.

It has a radius of approximately 0.25 cm,[1] 0.26 cm at the root.[2] The measured mean diameter can differ depending on the imaging method used. For example, the diameter was found to be 5.04 ± 0.74 mm using ultrasound, but 5.68 ± 1.19 mm using angiography.[3]

Asymmetries before reaching kidney

Due to the position of the aorta, the inferior vena cava, and the kidneys in the body, the right renal artery is normally longer than the left renal artery.

At kidney

Before reaching the hilus of the kidney, each artery divides into four or five branches; the greater number of these (anterior branches) lie between the renal vein and ureter, the vein being in front, the ureter behind, but one or more branches (posterior branches) are usually situated behind the ureter.

Each vessel gives off some small inferior suprarenal branches to the suprarenal gland, the ureter, and the surrounding cellular tissue and muscles.

One or two accessory renal arteries are frequently found, especially on the left side since they usually arise from the aorta, and may come off above (more common) or below the main artery. Instead of entering the kidney at the hilus, they usually pierce the upper or lower part of the organ.

Diseases of the renal arteries

Renal artery stenosis, or narrowing of one or both renal arteries will lead to hypertension as the affected kidneys release renin to increase blood pressure to preserve perfusion to the kidneys. RAS is typically diagnosed with duplex ultrasonography of the renal arteries. It is treated with the use of balloon angioplasty and stents, if necessary.

Atherosclerosis can also affect the renal arteries and can lead to poor perfusion of the kidneys leading to reduced kidney function and, possibly, renal failure.

Additional images

References

  1. Renin-Dependent Hypertension Caused by Nonfocal Stenotic Aberrant Hypertension. 46(2):380-385, August 2005.Kem, David C.; Lyons, Daniel F.; Wenzl, James; Halverstadt, Donald; Yu, Xichun
  2. Mathematical Modelling in Medicine. by Johnny T. Ottesen, Michael Danielsen - 2000 - Medical - 235 pages
  3. http://emedicine.medscape.com/article/463015-overview Aytac SK, Yigit H, Sancak T, et al. Correlation between the diameter of the main renal artery and the presence of an accessory renal artery: sonographic and angiographic evaluation. J Ultrasound Med. May 2003;22(5):433-9; quiz 440-2.

External links

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